I got this all mounted up tonight, went alright, i had to rip apart the rear hvac and just plug the harness in to the one circuit board while i was able to disconnect and remove the board the knobs are connected to, so it's just one small circuitboard floating around in my roof liner, which allows me to retain control fo the rear from the front controls.
the only negative i have to say about this whole thing thus far is the fact that the hvac already had a hole in the liner, so i had to put the screen a little farther back than i wanted, just to cover the hole, but it's not a big deal... the other thing is the front corners have a HUGE gap... but that's because i bouht a cheap monitor from ebay without a bezel, but i figure i'll just get some thick rubber and cut it to the contour of the roof, and glue it to the inside of the screen's casing, so it kind of closes the gap... but it's not too terrible as it is. Also i had to cut the roof liner, which, with the rear hvac, i cant imagine would be cheap to replace, so i was really hoping to avoid doing that... but that's fine, i intend to have the truck until it goes to the wreckers.
all i have to do now is finish putting in my 1000w power inverter below the front lower console (and install the plugs etc...), and then reinstall the front lower console, which i modified to put my dvd player in the CD "pocket"... then i still have my second battery to install and i am done... for now